Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Digital Sextant
    From: Vic Fraenckel
    Date: 2002 Apr 2, 08:41 -0500

    Dan Allen wrote:
    | I wonder what kind of silicon sensors exist that act as artificial
    | and what kind measure angles, and how accurately?  The digital compasses
    | recently referred to are accurate to 2 degrees.  For a sextant the angle
    | needs to be measured to a few seconds of arc to be competitive.
    In discussing the Digital Sextant, one must NOT confuse a digital compass
    with the method of measuring altitude. A sextant is NOT used to measure
    azimuth so to quote the accuracy of a digital compass module as an argument
    against the possibility of building a Digital Sextant clouds the issue. I
    have personally used digital optical encoders that can measure an angle to
    360/4096 degrees = 0.088 degrees = 5.27 minutes. The encoder resolves 360
    degrees into 4096 counts. While this does NOT come close to what would be
    needed to make the Digital Sextant, it is a device I am familiar with. There
    exists encoders that have even higher resolution.
    There also exists a integrated circuit device (Analog Devices ADXL202) which
    can measure it's own relationship to the the earth's gravitational field and
    who's output is a measure of the angles it makes with the gravitational
    field in two axes.  I have used this device as well..
    I have interfaced both devices to a microcontroller with ease and made
    useful measurements with them. Perhaps a Digital Sextant is not so far
    fetched after all!
    Victor Fraenckel - The Windman                 vfraenc1@nycap.rr.com
    KC2GUI                                                      www.windsway.com
          Home of the WindReader Electronic Theodolite
                                   Read the WIND

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site